Method for processing fish heads and apparatus for separating processed fish heads

ABSTRACT

A fish head, after being heated and softened, is broken down into its nose cartilage and various residues by being rotated and crushed, after a fish head. The method of processing a fish head also includes the following steps: separating the nose cartilage into an end proboscis part and a rear part; making a paste by removing fats after making comminutions of the cartilage; making a paste by removing the fats after making comminutions of the end proboscis part; making a paste of the aforesaid rear part; making a raw material from which to extract chondroitin sulfate, after removing the fats of the nose cartilage; making a powder from the paste of the end proboscis part; and making a powder from the paste of the rear part. Through the above methods it is possible to break down a fish head into its various parts easily and accurately; in particular, to separate the nose cartilage from the rest of the fish head, to break down the nose cartilage into the end proboscis part and the rear part, and to make the above parts, including the residues, into products having forms that are easy to handle and utilize.

BACKGROUND OF THE INVENTION

1. Field of the Invention

This invention is intended to serve as an apparatus that utilizes amethod of processing fish heads and separating them into their variousparts, thus making possible the effective use of fish heads, whichgenerally are treated as fish-processing waste.

2. Description of the Prior Art

In recent years, the aquaculture of fish, especially salmonids, has beenincreasing greatly, and it is said that more than 200,000tons of chumsalmon are produced in Japan each year. However, the consumption ofso-called salted salmon with the head intact is decreasing in Japan, asthe eating habits in this country change. In contrast, the production offlaked food, dried dainty salmon without the head, and thickly slicedfish fillet is increasing remarkably. In producing these foods, the fishhead is cut off by a machine and almost all of the heads are disposed ofas fish-processing waste. The disposal of such waste is becoming asocial problem, and it is anticipated that the volume of such so-calledwaste will increase in the future.

However, the cartilage that is in the head of fish in the Chondrichthyesclass, such as sharks, is well-known for being sold as a health foodafter it is processed into a fine powder. But it is becoming difficultto acquire the cartilage of sharks, because this shark resource itselfis rare, in addition to being extremely expensive. Also, specialinternational regulations and other factors pose additional problems.Therefore, at present, there is much interest in effectively using thenose cartilage of fish of the Osteichthyes class, such as salmonids, asa substitute for shark cartilage, which is expensive and difficult toobtain.

However, the head of a salmonid is very unsanitary, with blood aroundthe gills, secretions in the epidermis, and so on. Moreover, it is easyfor a worker to have an accident while using a knife, such as a kitchenknife, to remove the nose cartilage from the head. In particular,because the epidermis is slippery, workers can easily lose their grip onthe fish head and cut their hands. Thus, this work is time consuming andrequires that workers pay close attention to what they are doing. As aresult, productivity is low and very costly. As a result, vigorousefforts are not being made to use the above-mentioned salmonid headeffectively, and there has been little study concerning the possiblenutritional value or other beneficial uses of the constituents of thenose cartilage of such a fish. Thus, the possible applications for usingsuch nose cartilage in or with various kinds of foods are not beingrealized.

Nose cartilage accounts for approximately 10.0% of the weight of thehead of a fish such as a salmon. Moreover, proteoglycan, which is aconjugated protein, exists in nose cartilage. Chondroitin sulfate is anacid mucopolysaccharide that removes a particular protein fromproteoglycan. Related to this, a recent study showed the following:Chondroitin sulfate accounts for approximately 3.0% of the weight of thenose cartilage and for approximately 0.3% of the weight of the entirehead. In laboratory experiments, chondroitin sulfate has been extractedfrom the head of salmonids, particularly from the nose cartilage, andvarious studies relating to the medical effects of such chondroitinsulfate have begun. However, if the cost of producing nose cartilage,which is the necessary raw material from which chondroitin sulfate isextracted, is considered, the cost of producing chondroitin sulfate isvery high. Productivity is low because there is not available a systemthat improves the cost performance relating to the use of fish heads. Asa result, the manufacture of chondroitin sulfate from the heads ofsalmon is limited to the small-scale level of refinement that ispossible in a laboratory.

Chondroitin sulfate accounts for approximately 0.3% of the weight of theentire salmon head. However, although the head itself is waste and thepurchasing cost pr sales value thereof is zero, the cost of extractingchondroitin sulfate for business purposes is very high. If all of thedirect and indirect costs—such as the transportation cost sanddeep-freezing storage fees for the head; personnel expenses; lightingand heating costs; machine and equipment expenses; and so on—involved inextracting chondroitin sulfate, which constitutes only 0.3% of theweight of the head, are totaled, to extract such chondroitin sulfate istoo expensive to be conducted as a business. The high costs are a bigfetter that in effect prohibit the production of chondroitin sulfate.

Because the cost of producing only chondroitin sulfate is too high, itis not feasible as a business activity. The solution to this problem,therefore, is to develop a processing method that offers high costperformance by using, in addition to the nose cartilage, the other partsof the fish head; i.e., the residues that account for 90% of the weightof the head. In addition, an improvement (i.e., increase) in thepercentage of chondroitin sulfate (which has a high value) that isextracted from the raw materials, also is necessary.

The objective of the subject invention is to solve the above-mentionedproblems by serving as an apparatus that easily and accurately: (1)processes fish heads so as to separate them into their various parts,and especially to separate the nose cartilage from the rest of the fishhead, (2) separates the end proboscis part and the other rear parts fromthe nose cartilage, (3) processes the above various parts of the fishhead, including the residues, into forms that can be used inmanufacturing products of commercial value.

SUMMARY OF THE INVENTION

The subject invention's method of processing a fish head has thefollowing characteristic step: to break apart a fish head and toseparate the nose cartilage from various residues by rotating the fishhead and giving an impulsive force to it after it has been heated andsoftened.

In more detail, a fish head is heated and softened and then the hot fishhead is put into a rotary drum of which the surface is a round net-likebody. A plurality of plate blades are affixed either to the inside ofthe rotary drum or to the shaft of the drum, opposing each other in thedirection of the drum's circumference and axial plane, respectively. Byrotation of the rotary drum, the fish head is rotated and crushedagainst the plate blades and then the fish head is separated into thenose cartilage and various residues.

In the second step of the process of separating the aforesaid nosecartilage into the end proboscis part and the rear part, the nosecartilage is put into the aforesaid rotary drum of which the surface isa round net-like body. A plurality of plate blades are affixed either tothe inside of the rotary drum or to the shaft of the drum, opposing eachother in the direction of the drum's circumference and axial plane,respectively.

Moreover, the method of this invention comprises the following steps:making paste by removing fats after making comminutions of theabove-mentioned nose cartilage that has been separated by the aforesaidprocess, making a meal by grinding the aforesaid residues; making apaste by removing fats after making comminutions of the aforesaid endproboscis part; making a paste of the aforesaid rear part; making a rawmaterial from which to extract chondroitin sulfate after removing thefats of aforesaid nose cartilage; making a powder from the paste of theaforesaid end proboscis part; and making a powder from the paste of theaforesaid rear part.

This invention's apparatus for separating the processed parts of a fishhead of that is used in the aforesaid methods of processing comprises: ashaft that rotates by being driven by a rotating means; a plurality ofsupport members that are separately joined to the shaft in the axialdirection of the shaft; a rotary drum made of a net-like body that isrounded at the aforesaid support members, that forms a processing spaceinto which is put hot said fish head (in particular, the net-like bodyof the rotary drum being formed by a plurality of reticles that are ofvarious sizes according to the desired type of processing of theaforesaid fish head), and that is freely movable from said supportmembers and is exchangeable; and a plurality of plate blades that areinstalled in the rotary drum and that project into the aforesaidprocessing space.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic illustration showing the structure of theseparation unit of the apparatus that is explained for the bestembodiment of the invention.

FIG. 2 shows two side-plane views of FIG. 1, with FIG. 2(a) showing afront view of the right end of FIG. 1, and FIG. 2(b) showing a frontview of the left end of FIG. 1.

FIG. 3 is a two-part schematic illustration showing the structure of theheating unit of the apparatus that is explained for the best embodimentof the invention.

FIG. 3(a) is a cross-section view and FIG. 3(b) is a greatly enlargedcross-sectional view of the metal vessel.

FIG. 4 is a drawing of a fish head.

FIG. 5 is a three-part drawing of the nose cartilage of a fish head,with FIG. 5(a) showing a side view, FIG. 5(b) showing a view of the topsurface, and FIG. (c) showing a view of the base surface.

FIG. 6 is a three-part drawing of the nose cartilage of a fish head,with FIG. 6(a) being a side showing a line that separates the endproboscis part from the rear part of the nose cartilage, FIG. 6(b) beinga drawing of an end proboscis part after separation of the nosecartilage, and FIG. 6(c) being a drawing of the rear part of thecartilage after separation of the nose cartilage.

FIG. 7 is a schematic illustration showing the structure of theseparation unit of the apparatus in the process of separating a nosecartilage into an end proboscis part and a rear part.

DETAILED DESCRIPTION OF THE INVENTION

Best Embodiment of the Invention

This apparatus mainly comprises the separation unit 10, which is shownin FIG. 1 and FIG. 2, and the heating unit 20, which is shown in FIG. 3.

In the separation unit 10 there is a rotary drum 11 that has a circularcylindrical shape. The surface of this rotary drum 11 is a roundnet-like body, like a wire netting or a punchboard, that is open at bothends 11A and 11B. As shown in FIG. 1, which depicts an example of anembodiment of this invention, the shapes of the reticular openings ofthis net-like body range from large rectangular ones 11 a and smallrectangular ones 11 b. However, it is possible for the reticularopenings to be, in addition to the rectangular shapes 11 a and 11 b, ofvarious other shapes, such as a polygonal shape like a rhomboid, or ahalf-circle, circle, or oval, among others. It also is possible for aplurality of the above-described shapes to be combined.

A shaft 13 is placed inside and affixed to this rotary drum 11 throughthe support members 12 at the axial center of this rotary drum 11. Bothends of this shaft 13 are supported by two support brackets 14A and 14Bthrough bearings 14 a and 14 b, respectively, in this working example.In particular, the rotary drum 11 and the shaft 13 are supportedtogether by the support bracket 14; therefore, this axial line is in thehorizontal direction and is located at a fixed distance from the bottomof the drum, and the rotary drum 11 and the shaft 13 are freelyrotatable as a unit.

The two support brackets 14A and 14B have four legs 15 that are mountedtwo on both sides, and a wheel 16 is installed at the bottom tip of eachof these four legs 15; because these wheels 16 can roll, the entireseparation unit 10 is freely movable. As shown in FIG. 2(a) (which showsa front view of the right end of FIG. 1), a bearing 14 a is installed inbracket 14A, which is placed at the entrance end of the drum, and theshaft 13 is supported by the bearing 14 a.

In addition, as shown in FIG. 1 and FIG. 2(b) (which shows a front viewof the left end of FIG. 1), a bracket 14B is attached to the drivingmechanism 17 at the exit end of the drum. In this driving mechanism 17,a drive motor 17 a is connected to the shaft 13 through the chain belt17 b and the sprockets 17 c, and the chain belt 17 b is covered by thechain cover 17 d. Therefore, when the drive motor 17 a is in operation,this rotating power is transmitted to the shaft 13 through the chainbelt 17 b and the sprockets 17 c, and the rotary drum 11, which isunited with this shaft 13, rotates around the axis center. The table 18,which extends out from side to side in a horizontal direction, isaffixed to the shaft 13 by the entrance-side bracket 14A.

Moreover, a plurality of plate blades 19 are affixed either to theinside of the rotary drum 11 or to the shaft 13. The plate blades 19that are affixed to the inner surface of the rotary drum 11 extend fromthe inside of the drum 11 in the direction of the shaft 13. In contrast,the plate blades 19 that are affixed to shaft 13 extend from the shaft13 in the direction of the inner surface of the rotary drum 11. All ofthe plate blades 19 are affixed either to the rotary drum 11 or to theshaft 13, opposing each other in the direction of the drum'scircumference and axial plane, respectively.

As an example of the embodiment, the heating unit 20 is illustrated inFIG. 3. The heating unit 20 has within it a housing 23, which is arectangular box whose upper side is open. Inside the housing 23 are aplurality of metal vessels 24, each of which has a plurality of holes 24a on its base plane and its four side planes.

When the above-described housing 23 is filled with boiling water, theboiling water enters into the vessel 24 through the holes 24 a.Therefore, when fish heads are put into the vessel 24, they are heatedby the boiling water in the vessel 24. In this implementation example,hot water is used as the means for heating the fish heads, but theheating can also be realized by using an iron steam pot, as just oneother example of other possible means.

Next, an embodiment of the operating process, using the separationapparatus comprised as described above, will now be described in detail.

A fish head 1 (FIG. 4), which was cut off in a fish-processing factoryor other facility and then collected for shipment as cargo, is put intothe vessel 24 of the heating unit 20. The fish head 1 that has been putinto the vessel 24 is heated with boiling water, and thermal deformationoccurs in the epidermis, fat, muscles, and so on of the fish head 1, andthen lysis or solidification occurs, as a result of which it becomeseasy for the entire head, which includes cartilage, hard bones, andgills, to collapse.

Next, the fish head 1, which has been heated in the heating unit 20, isput into the opening of the entrance 11A of the rotary drum 11. Then, asa result of the operation of the drive motor 17 a, the rotary drum 11rotates, the fish head 1 in the rotary drum 11 is rotated by therotation of this drum 11 and is moved forward and then crushed by beingstirred by the plate blades 19. Because the fish head 1 has been heatedand softened, it is easy for the head to collapse while being moved fromthe entrance of the rotary drum 11 to the exit thereof. The fish head 1is separated into residues such as the nose cartilage 2, the hard bones,the gills, the epidermis, and the muscles, which are collected from theopening 11B of the exit side of the rotary drum 11.

The round surface of the rotary drum 11 is a reticular-like figure, andthe residues such as the hard bones, the gills, the skin, the muscle,and so on become minute in size and fall through the reticular spaces tothe outside of the rotary drum 11. Therefore, only the nose cartilages 2remain in the rotary drum 11, and they are carried to and passed throughthe opening at the exit side and collected there. If the reticularopenings of the net-like body are sized and shaped appropriately, asrectangles, polygons, half-circles, circles, or ovals, and so on, andare combined as mentioned above, each type of minute residue, such asthe hard bones, the gills, the epidermis and the muscles, will fallthrough its respective reticular openings, and all of the residue willbe collected together underneath the net-like body, and the nosecartilage 2 can easily be removed.

Concerning the separating apparatus of this invention, no liquid, suchas water, is used in the separation process. Therefore, in the rotarydrum 11, the fish head 1 is subjected to a directive and strong crushingforce and is easily collapsed and separated into its component parts.Because the fish head 1 is carried from the entrance side to the exitside of the rotary drum 11 within about 3 minutes, the nose cartilages 2are able to be continuously gathered in large quantities in a shorttime. Also, because processing the fish head with this invention doesn'tinvolve the use of water, no unsanitary sewage is generated. Moreover,the processing is easy because there is no moisture in the residues,such as the hard bones, gills, epidermis, or muscle, that fall throughthe reticular openings.

Because this apparatus is small and freely movable, it call be easilyused in fish-processing factories anywhere.

Although the following was not illustrated in FIG. 1 through FIG. 3, byinstalling a belt conveyer and a receiving board, and so on under therotary drum 11, a receiving board can be used to prevent scattering ofthe falling residues. The residues are then transported by a beltconveyer for subsequent processing.

Next, an embodiment of the defatting process will now be described indetail.

The nose cartilage that was separated and removed by the aforesaidprocess is made into comminutions above a mixer, and the fat nodules areexposed on the surface of the comminutions. In this process, a similareffect can be obtained by using, as an alternative, a cutting apparatus(having an edge), such as a slicer, that can cut thinly.

Either the comminutions or the sliced pieces of the nose cartilagementioned above are put into a cleaning tank (not shown in a figure),and those items are defatted through a process of well washing with coldor hot water.

Because thermal denaturation and oxidization can easily occur, eitherthe comminutions or the sliced pieces of the nose cartilage that havebeen defatted by the above-mentioned method are rapidly frozen in a deepfreezer immediately after they have been dehydrated.

The frozen nose-cartilage comminutions that have been made by theabove-mentioned process are removed from the deep freezer and thenimmediately put into a kneading machine, such as a chopper or a silentcutter, so as to make a paste of the nose cartilage. By theseprocedures, a high-quality paste that is neither denatured nor oxidizedcan be made.

The residues, such as hard bones, gills, epidermis, muscle and so on,that are separated in the above-mentioned process, comprise 90% of thefish head in terms of weight. The residues are easy to treat in afurther process, because 100 g of the residues include 67.1 g ofmoisture. In addition to the above, 100 g of the residues comprises 16.6g of protein, 1,500 mg of calcium, 10.8 g (including 1,160 mg of DHA and1,240 mg of EPA) of lipids, and other minor components, such ashydroxyproline, taurine, minerals, amino acids, and so on, in a goodbalance. As is described above, the residues contain many usefulingredients and rich nutrients.

The above-mentioned residues are transported by a belt conveyer that isplaced under the separation apparatus 10, and they are then ground by achopper or a silent cutter so as to make a meal, and then the meal ofthe residues is rapidly frozen in a deep freezer.

It is possible to make food, of which the commodity value is high, forthe aquaculture of fish and/or feed for domestic animals, by adding theliver of the fish to the aforesaid meal, thereby increasing the amountof vitamin A, and by adding albino, thereby supplementing nucleic acidsand restraining the generation of active oxygen.

An embodiment of the process of making a raw material from which can beextracted chondroitin sulfate, of which the commodity value is high,will now be described in detail.

As FIG. 6 illustrates, the nose cartilage comprises the end proboscispart 21, which is composed only of cartilage, and the rear part 22,which is composed of cartilage and hard bones, with the two parts beingfirmly combined with each other. However, the nose cartilage can easilybe broken along the dotted line indicated in FIG. 6(a) when suitableforce is applied along the oblique line indicated in that figure. Inthat way, by applying an impulsive force and vibration, the nosecartilage is separated into the end proboscis part 21, which is composedonly of cartilage, and the rear part 22, which is comprised of cartilageand hard bones.

FIG. 7 shows the separating apparatus that separates the nose cartilage2, which was previously separated from the fish head in the primaryprocess, into the end proboscis part 21 and the rear part 22.

A description of the structure of this apparatus is omitted here becausethe structure of this apparatus is almost identical to the one shown inFIGS. 1 and 2 and previously described.

As shown in FIG. 7, the nose cartilage 2 is put into the opening atentrance 11A of the rotary drum 11. Then, as a result of the operationof the drive motor 17 a, the rotary drum 11 rotates, the nose cartilage2 in the rotary drum 11 is rotated by the rotation of this drum 11 andis moved forward and crushed by being stirred by the plate blades 19.While the nose cartilage 2 is being carried from the entrance of therotary drum 11 to the exit thereof, (1) the nose cartilage is separatedinto the end proboscis part 21 and the rear part 22, (2) the endproboscis part 21, which is comprised only of soft cartilage, is brokeninto minute tips that fall through the reticular openings of thenet-like body, and (3) the rear part 22, which includes hard bones,passes out of the rotary drum 11 through the opening 11B on the exit endof the rotary drum 11, alter which it is collected.

Chondroitin sulfate, which comprises 2.9%-3.0% of the weight of theentire nose cartilage, comprises 4% of the weight of the end proboscispart that is collected by the aforesaid process. Thus, the thechondroitin sulfate content of the end proboscis part is 25% or morehigher in concentration than that of the nose cartilage taken as awhole. The paste that is made from this end proboscis part has highcommodity value as raw material from which chondroitin sulfate can beextracted.

Moreover, the aforesaid the end proboscis part 21 is made intocomminutions in such a way that their fat nodules are exposed on theirsurfaces. The comminutions are then put into a cleaning tank anddefatted by washing them with cold or hot water. In this process, thefat contents of the end proboscis decreases from 10.0% to 0.3% in termsof weight. The end-proboscis particles that have been defatted by theabove-described method are rapidly frozen in a deep freezer and are madeinto a paste by a kneading machine.

In contrast, the entire rear part is made into a paste, because thecartilage in the rear part is firmly combined with the hard bones, andit is difficult to separate them from each other. The paste of the rearpart is useful as a highly functional food material of which thecontents of calcium, DHA, and EPA are higher than in the end proboscis,while the chondroitin sulfate content is lower in the rear part than inthe end proboscis. This rear-part paste also is frozen.

Through the process of freeze drying, powders can be obtained from bothof the frozen pastes—that from the end proboscis and that from the rearpart—that have been made by the method described above. These twopowders can be used as additives in pharmaceuticals, cosmetics, healthfoods, and so on, without further processing.

Effects of the Invention

By this invention it is possible to separate a fish head into itsvarious parts; in particular, to break down a fish head into its nosecartilage and various residues, and then to separate the nose cartilageinto its end proboscis and rear parts. It also is possible to make apaste or powder of each of the various parts, including the residues,that have been separated from the fish head. The paste and powder can beoffered for use in other manufacturing products.

In addition, the apparatus can easily be installed in fish processingfactories anywhere, because the apparatus for this method of processinga fish head is simple, small and, and inexpensive. In addition, thegeneration of fish-processing waste can be limited.

Moreover, it is possible to provide a raw material from which to extractchondroitin sulfate at a low cost that makes feasible its use formedical purposes.

EXPLANATION OF NUMBERS IN FIGURES

1 fish head

2 nose cartilage

10 separation unit

11 rotary drum

11 a, 11 b rectangular reticular openings

12 support member

13 shaft

14 support bracket

14 a, 14 b bearings

15 legs (4)

16 wheels (4)

17 drive mechanism

17 a drive motor

17 b chain belt

17 c sprockets

17 d chain cover

18 table

19 plate blades

20 heating unit

21 end proboscis part of nose cartilage

22 rear part of nose cartilage

23 housing

24 metal vessel

24 a holes

What is claimed is:
 1. An apparatus for separating fish each havingfirst and second parts, comprising: a rotary drum formed as a net-likebody and defining therein a processing space for receiving said fish; arotatable shaft extending in said processing space, along an axialdirection of said drum, and driven by a rotating mechanism; and aplurality of plate blades each installed in said processing space andextending from one of said drum and said shaft toward the other of saiddrum and said shaft, for facilitating separation of said first andsecond parts of said fish when said shaft is rotated by said rotatingmechanism.
 2. The apparatus of claim 1, further comprising a pluralityof support members for fixing said drum and said shaft together.
 3. Theapparatus of claim 1, wherein said net-like body of said rotary drumincludes a plurality of reticular openings shaped and sized to allowsaid first parts of said fish to pass through while retaining saidsecond parts of said fish in said processing space.
 4. The apparatus ofclaim 1, wherein said drum and said shaft are configured to be freelyrotatable as a unit.
 5. The apparatus of claim 1, wherein said drum andsaid shaft are disposed substantially horizontally.
 6. A method ofprocessing a fish head, and comprising the steps of: separating the nosecartilage and residues other than the nose cartilage from said fishhead, making paste by removing fats after making a comminution of saidnose cartilage, and pulverizing said residues.
 7. A method, as claimedin claim 6, for separating the end proboscis part and the rear part fromsaid nose cartilage, making said paste by removing fats after makingsaid comminution of said end proboscis part, and making said paste ofsaid rear part.
 8. A method as claimed in claim 7, of making a rawmaterial from which to extract chondroitin sulfate after removing fatsfrom said nose cartilage.
 9. A method as claimed in claim 7, ofpulverizing said paste after making said paste from said nose cartilageor said end proboscis part.
 10. A method as claimed in claimed or claim6, of making a raw material from which to extract chondroitin sulfateafter removing fats from said nose cartilage.
 11. A method as claimed inclaim 6, of pulverizing said paste after making said paste from saidnose cartilage or an end proboscis part.